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A series of homogeneous AgGa(S1−xSex)2 solid solution nanocrystals with controllable composition (0 ≤ x ≤ 1) have been successfully prepared through a facile colloidal synthesis approach. Remarkably, they exhibit an evident crystal phase transformation from orthorhombic to tetragonal along with the chemical composition of particles from either S or Se excess to S/Se approximate equality. The factors to determine this phase-selective synthesis of AgGa(S1-xSex)2 nanocrystals could be probably attributed to the relatively weak reactivity of Ga3+ in the oleylamine-based reactive system and the metastable terminal possessed by AgGa(S1-xSex)2, which was proposed after investigating their nucleation mechanisms. Furthermore, the photocatalytic potential of the as-synthesized AgGa(S1−xSex)2 nanocrystals has been evaluated through degrading methyl violet under visible-light illumination. Benefiting from the optimized crystal phase and energy structure, AgGa(S0.7Se0.3)2 presents the optimal photocatalytic efficiency of 88.48%. [ABSTRACT FROM AUTHOR]

Main conclusion: Natural 2n female gametes and transmission of parental heterozygosity by natural 2n gametes in Populus tomentosa are reported for the first time, which provides a new approach to polyploid breeding.Abstract: Naturally occurring 2n pollen is widespread in Populus tomentosa and plays an important role in polyploid breeding. However, the competitiveness of 2n pollen is lower than that of haploid pollen during pollination and fertilization, so 2n pollen is less efficient at fertilizing haploid female gametes to produce polyploids. In theory, polyploids can also be obtained when 2n female gametes are fertilized by haploid pollen. Thus, the question becomes whether natural 2n female gametes exist in P. tomentosa, which can be answered by examining the genetic composition of natural 2n gametes. In this study, the origin of 87 triploids from the hybrid combination “X-2 × Z-5” was identified by SSR markers and 21% of natural 2n gametes were found to originate from female parents. Four SSR loci with low recombination rates were used to identify the genetic composition of natural 2n gametes. The results showed that the genetic composition of 2n female gametes was mainly characterized by SDR, while 2n male gametes were mainly produced by FDR. Moreover, the transmission of parental heterozygosity by natural 2n gametes, which is significantly different between female and male parents in FDR and SDR types, was analysed using 42 SSR primers. Here, we report naturally occurring 2n female gametes for the first time in P. tomentosa and reveal the genetic constitution and transmitted parental heterozygosity of these gametes. Our results provide a foundation for theoretical research into 2n gametes and their application in new polyploid breeding strategies. [ABSTRACT FROM AUTHOR]

A series of the novel zinc complexes, Zn3(H2L1)2(ox)3(H2O)2·4H2O (1), Zn(H2L1)(ad)·2H2O (2), Zn2(HL2)2(suc)0.5·(HCOO)·H2O (3), Zn2(HL2)2(glu)·2H2O (4), Zn2(HL2)2 (ad)0.5·(OH)·0.5H2O (5), Zn2(HL2)2(seb)(H2O)·2.5H2O (6), (H2L1 = 2,6-di(5-methyl-1H-pyrazol-3-yl)pyridine, H2L2 = 2,6-di(5-phenyl-1H-pyrazol-3-yl)pyridine, H2ox = oxalic acid, H2ad = adipic acid, H2suc = succinic acid, H2glu = glutaric acid, H2seb = suberic acid) were synthesized hydrothermally from the self-assembly of a Zn(ii) ion with different types of the new bi-pyrazolyl pyridine derivative ligands and different spanning flexible dicarboxylic compounds as an auxiliary ligand. They were characterized by elemental analysis, IR and UV–vis spectroscopy, powder X-ray diffraction (PXRD) and single-crystal X-ray diffraction. We found that they are all molecular compounds using the above detections. The structural analysis indicates that the zinc atom in complex 1 is a six-coordinate mode of ZnO3N3, forming a slightly distorted octahedral geometry, while zinc atoms in complexes 2–6 are all penta-coordination modes of ZnO2N3 and ZnON4 in a distorted bipyramidal geometry. The H2L1 ligand is in the form of a μ1–η1–η1–η1 coordination with metallic Zn in 1 and 2; while the HL2 ligand is in a μ2–η1–η1–η1–η1 coordination mode in 3–6. For the oxalate ligand, there are two kinds of coordination modes, μ2–η1–η1–η1–η1 bridging coordination mode and μ1–η1–η1 terminal coordination mode; the coordination mode of glutaric acid ligand is in the form of μ2–η1–η1; suc2− ligand is in the form of a μ4-bridging coordination fashion with each side carboxylate group in a μ2–η1–η1-monodentate mode; the coordination of the adipic acid ligand presents two coordination modes of μ2–η1–η1and μ4–η2–η2; suberic acid ligand acts in a monodentate terminal coordination mode. In addition, thermal behaviors and photoluminescent properties for 1–6 were all performed and are discussed in detail. The catalytic activity of the complexes is evaluated firstly by the reaction of hydrogen peroxide promoted oxidation of cyclohexane and cyclopentane under mild conditions. It is found that the Zn complexes with five different spanning flexible dicarboxylic acids as an auxiliary ligand with oxalic acid, succinic acid, glutaric acid, adipate acid or sebacic acid, respectively, have potential catalytic activity in the oxidation reaction of cyclohexane. [ABSTRACT FROM AUTHOR]

The reaction of VO(ph-acac)2 (ph-acac=phenyacetylacetonato) with NaHB(pz)3 (pz=pyrazole) or NaHB(3,5-Me2pz)3 in the solution of MeOH gave oxovanadium (IV) complexes HB(pz)3VO(ph-acac) · 2H2O (1) and HB(3,5-Me2pz)3VO(ph-acac) · 2H2O (2), respectively. An oxovanadium complex, V2O4[HB(pz)3]2 · 2CH3CN (3), was obtained by the reaction of VOSO4 · 3H2O with tri(pyrazolyl)borate sodium in MeOH. The complexes 1, 2 and 3 were characterized by elemental analysis, IR, UV-Vis, NMR. In particular, the crystals of complex 1 and 3 were determined by X-ray diffraction. They crystallize in space group P21/c, a=16.497(5) Å, b=7.6601(19) Å, c=17.199(4) Å, β=107.498(19)°, V=2072.8(9) Å3, Z=4, R=0.0371 (I>2σ(I)) for 1; in the monoclinic, space group Pbca, with cell dimensions of a=15.531(2) Å; b=18.007(2) Å; c=10.725(2) Å; V=2999.4(8) Å3, Z=4, R= 0.0401(I>2σ(I)) for 3. Structure analyses have shown that complex 1 is a monomeric oxovanadium complexe containing polypyrazolylborate and two lattice water. Complex 3 consists of a V2O4(HB(pz)3)2 molecule and two free CH3CN lattice molecules in an unit cell. Both possess a similar coordination mode for the vanadium atom. In addition, luminescence properties and thermal analysis characterization of the complexes also are discussed. [ABSTRACT FROM AUTHOR]

At room temperature, two new different oxovanadium complexes with simple pyrazole (C3H4N2) as ligand were synthesized. VO(pz)4(SO4)·H2O (1) (pz: pyrazole) is a mono-nuclear oxovanadium complex with pyrazole as terminal ligands. V2O2(μ-pz)(μ-OOSO2)(μ-OCH3)(pz)4 (2) is bi-nuclear oxovanadium complex containing three different bridges, which are pyrazolate, sulphate and methoxy, respectively. The two complexes were characterized by IR, elemental analyses, thermal analyses and X-ray diffraction. The crystal structural data of the complexes 1 and 2 are given as follows: Complex 1, orthorhombic, Pna21, a =14.547(2) Å, b =10.895(2) Å, c =11.835(2) Å; α=β=γ=90°; V=1875.8(5) ų, Z = 4, R1 = 0.0485, wR2= 0.1092. Complex 2, triclinic, P1, a =8.377(2) Å, b =9.928(2) Å, c = 16.527(3) Å, α = 85.54(3)°, δ = 80.92(3)°, γ = 87.92(3)°, R1= 0.1461, wR2 = 0.4444. The study of non-thermal kinetic de- composition shows that, for complex 1, the possible reaction mechanisms of the two steps are nucleation and growth n=1/3, and three-dimensional pervasion n=2, respectively, and the kinetic equations may be expressed as da/dT = (A/β)exp(-E/RT){1/3(1-α)[-ln(1-α]-2} and da/d T = (A/β)exp(-E/RT){3/2(1-α)2/3 [1-(1-α)1/3]-1}, respectively; for complex 2, the possible reaction mechanisms of the two steps are chemical reaction, and three-dimensional pervasion n=2, respectively; the kinetic equations may be expressed as da/dT = (A/β)exp(-E/RT)[(1-α)ଡ], and dα/d T = (A/β)exp(-E/RT){3/2(1-α)2/3[1-(1-α)1/3]-1}, respectively. [ABSTRACT FROM AUTHOR]